1. Field of the Invention
The present invention relates to a vertically adjustable work table with at least two support legs. The work table includes a lower frame with at least two outer tubes which each form a part of one of the support legs and are spaced apart from each other and are connected to each other, and an upper frame composed of a work plate and two inner tubes guided in the outer tubes and also forming parts of the support legs, wherein the inner tubes are movable by means of traction ropes connected to a traction unit, and wherein the traction ropes are attached to the top of the lower frame, extend downwardly toward the bottom of the inner tube and are guided from the bottom of the inner tube toward the upper portion of the outer tube and outwardly into the lower frame.
2. Description of the Related Art
Work tables, which also can be called desks and work benches and which are composed of a metal frame supporting a work plate, are known in the art. The frame is composed of a lower frame which is formed by at least two outer tubes which are connected to each other through a strut and may have different cross-sectional shapes and cross-sectional sizes. Inner tubes are slidably guided in the outer tubes, wherein the inner tubes are connected either exclusively to the work plate or, if necessary, they may be connected through an additional strut. An outer tube and an inner tube always together form a support leg of the work table. In order to be able to change or raise the vertical position of the work plate, a rope is attached to the upper portion of the lower frame, preferably to the upper portion of the outer tube, wherein the rope extends downwardly toward the lower end of the inner tube, is deflected at the lower end of the inner tube and then again extends upwardly and then projects in the upper portion of the outer tube into the lower frame and is received in the lower frame by a traction unit which may be composed, for example, of a rope drum. All of the ropes of the support legs are connected to the traction unit. By appropriately moving the traction unit, the inner tubes are pushed out of the outer tubes gradually, but within predetermined limits, so that the work plate is raised. When the traction unit is moved in the opposite direction, the traction ropes are released and the inner tubes once again move back into the outer tubes as a result of the weight of the upper frame, particularly of the work plate. The traction unit may be moved either manually or by a special drive.
A work table of this type has the disadvantage that the work plate can no longer be lowered if an inner tube is misaligned in an outer tube and becomes jammed. An even greater disadvantage is the fact that, when the work table is to be grasped, for example, at the work plate and is to be carried, the work plate moves upwardly and the inner tubes move out of the outer tubes until the maximum work level of the work plate has been reached. When the work plate is at this vertical position, it is usually no longer possible to carry the work table.